The inventive subject matter relates to a digital broadcasting system, and more particularly, to an equalizer for equalizing a vestigial side band (VSB) signal in a digital television (TV) system, and an equalizing method thereof.
Broadcasting systems are rapidly changing from analog broadcasting systems to digital broadcasting systems. Traditional analog broadcasting systems are expected to be fully replaced by digital broadcasting systems within the next several years.
Digital broadcasting systems may be classified as European-type and American-type. In Europe, the transmit/receive system of a digital broadcasting signal has been standardized into digital video broadcasting-terrestrial (DVB-T) based on orthogonal frequency division multiplexing (OFDM). In the United States, however, digital broadcasting systems have been standardized based on vestigial side band (VSB). A VSB signal is prescribed in advanced television systems committee (ATSC) standards.
An ATSC 8-VSB digital TV broadcasting system has been designed to account for the use of a roof-top antenna fixed. Accordingly, the ATSC 8-VSB digital TV broadcasting system may be more advantageous for a high-definition (HD) broadcasting compared to the DVB-T standard of Europe, but may be relatively disadvantageous for reception performance in a mobile environment. Several standards (e.g., DVB-H, MediaFLO, T-DMB, ATSC-M/H, and the like) have been proposed as alternatives for providing excellent reception performance in a mobile environment.
The new standards that have been developed as alternatives have contributed to improvement of mobile reception. However, it is generally desirable to modify existing broadcasting equipment and devices to be compatible with the new standards. Accordingly, a significant additional investment may be required to apply the new standards.
An approach for limiting additional investment is to enhance the performance of an ATSC digital TV receiver in a mobile environment. Core technology for enhancing performance of a mobile digital TV receiver includes an equalizer module. The equalizer module can compensate for multi-path channel effects generated in a mobile environment. In order to overcome multi-path effects, the equalizer may adapt a parameter to the fast channel environment at high speed. However, it is known that a receiver of a single carrier communication system, such as 8-VSB scheme, may not be capable of estimating a time-varying channel at high speed.